Conducting post-incident or after-action reports of Mayday incidents provides opportunities to examine positive actions on the fireground as well as missed opportunities.  The goal of these after-action reports is to improve the response for the next time.   Non-LODD incidents have the potential to provide a unique opportunity to collect information from the fire personnel involved in the incident. Studying these incidents with the advantage of firsthand accounts enables the most accurate representation of events.  The combination of firsthand experience with the knowledge gained from firefighting related research facilitates an objective determination of the factors that contributed to the outcome. The goal of the FSRI studies is to enhance the tactical effectiveness, situational awareness, and safety of firefighters by developing knowledge based on the application of fire dynamics research to these fire incidents.  To better understand the fire environment that firefighters have been exposed to, we examine their PPE: melted face shields, discolored gear, and damaged helmets.  Testing the equipment to document the thermal exposure needed to melt or pyrolyze the gear provides insight into the conditions that the firefighters were in.   This presentation will look at some of the common issues that come out of the deep dives, including the value of training, maintaining situational awareness, wearing all your PPE, and understanding your equipment.  Specifics from the case studies regarding the importance of size-up, using that information to drive the tactics, understanding flow paths, and being ready to pivot are essential lessons that can help firefighters and fire officers increase their effectiveness on the fireground.